The present invention relates to integrated circuit device analysis, and more particularly to electrical trace inspection during device analysis for devices with solder ball attachments.
With the advancements in semiconductor device technology, several different types of arrangements for integrated circuit devices have emerged. One arrangement involves the use of solder balls for attaching an integrated circuit device to a circuit board. Two examples of such devices are the fine-pitch ball grid array (FBGA) device and a micro ball grid array device (xcexcBGA) device. FIGS. 1 and 2 illustrate a partial cross-sectional diagram of a typical FBGA device and a typical xcexcBGA device, respectively.
As shown in FIG. 1, an FBGA device 8 typically includes an integrated circuit die 10 encapsulated in packaging material 12, e.g., an epoxy compound. Electrical connections for the die 10 are provided by bond wires 14, such as gold wires, coupling input/output pads on the die 10 to bond pads 16 of a die paddle 18, e.g., an elastomer material. The bond pads 16 electrically couple the die 10 to solder ball connectors 20 via traces 22, e.g., copper tracings, in a tape material 24, e.g., a polyimide tape. The solder ball connectors 20 capably attach the device 8 to a circuit board (not shown). As shown in FIG. 2, a xcexcBGA device 30 includes an integrated circuit device 32 electrically coupled to solder balls 34 via bond wire 36 and trace 38. The trace 38 is provided in a polyimide tape 40. An elastomer seal layer 42 supports the coupling of the die 32 and bond wire 36 to the tape 40.
While the advent of such devices attempts to overcome certain challenges facing circuit designers, the needs of device analysis for these devices are usually overlooked in the design process. In analyzing integrated circuit devices, such as those shown in FIGS. 1 and 2, part of the procedure is to visually inspect the traces and solder ball connections. Unfortunately, the small size and large number of the traces makes visual inspection a challenging process. Further hampering the visual inspection process is the polyimide tape in which the traces are secured. Normal polyimide tape is provided as colored material, e.g., usually blue or brown. Such coloring reduces the clarity of the visual inspection process, thus limiting the ability to perform desired device analysis fully.
Accordingly, a need exists for a manner of providing more successful visual inspection during device analysis. The present invention addresses such a need.
The present invention provides aspects for electrical trace inspection during device analysis for devices with solder ball attachments. In a method aspect, the method includes forming a desired integrated circuit device including bond wire attachments. The bond wire attachments are then utilized with electrical traces in a transparent tape layer, with visual inspection of the electrical traces performed through the transparent polyimide tape. In an apparatus aspect, the apparatus includes an integrated circuit die, the integrated circuit die including bond pads. The apparatus further includes bond wires coupled to the bond pads of the integrated circuit die, and a transparent tape layer, including a plurality of traces for electrically connecting to the bond wires, wherein visual inspection of the plurality of traces occurs through the transparent tape layer.
Through the present invention, more efficient and accurate device analysis occurs. The utilization of a transparent polyimide tape layer provides a straightforward technique of improving clarity during visual inspection of electrical traces in integrated circuit devices, such as FBGA and xcexcBGA devices. The improvement in clarity further reduces the time needed to inspect the traces and offers more reliable viewing of the traces. These and other advantages of the aspects of the present invention will be more fully understood in conjunction with the following detailed description and accompanying drawing